Blow-off valve.



c. EVANGE.

BLOW-OFF VALVE.

APPLIGATION FILED 1113.15, 1912.

Patented Sept. 9, 1918.

Wiibzesses: fizvenlor UNITED sTArn s r a rENT OFFICE.

CHARLES '21. valves, 0; gmssvm PENNSYLVANIA.

BLOW-err we.

Specification of Letters Patent.

, Application flied February is, 1912. Serial No. 677,135.

To "all whom, it mag concern:

Be it known that I', OHAnL'Es E. VANCE, a citizen of the United States, residing at Pittsburgh, in the count Y of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Blow- Ofi' Valves, of which the following is a specification.

My invention 'cdnsists of an improved blow oil valve construction adapted to close a circulation port by means of a double valve mechanism, carried on a single constructed and adapted to operate in the manner hereinafter. more fully set forth.

In the drawings: Figure 1 is a vertical sectional view through the device, showing both valves seated. Fig. 2 is a partial similar view showing the main valve partly raised.

The valve structure is generally similar to -others of well known form, com rising a casing 2 having an interior chain er 3, an-

inlet opening 4, an outlet opening 5, a valve stem '6 extending through a stuffing box 7 and an arbor or frame 8. and provided with a hand wheel 9.- Within the valve chamber is a valve seat, preferably formed of an inserted bushing 10, within which seats the main valve 11 rotatably mounted on the lower end of stem 6 and operable in the usual way to open or close the circulation of fluid through the valve. Surrounding the stem 6 and journaled upon it between an upper collar 12 and a lower collar 13, is the secondary valve 14 in the form of a shell, havin a depending skirt 15 adapted to substantia ly fill the cylindrical chamber 3 and to seat by its lower edges upon the upper face of bushing 10. Between the collar 12 and the middle journaled portion of the valve 14 is inserted a packing 16 of any suitable kind as asbestos cord, hemp, etc. and also a coiled spring 17 The effect of the spring is to hold the secondary valve 14 downwardly against collar 13, as in Fig. 2, and in an advanced position with relation to main valve 11, so that the edge of the.

5. Upon closing the valve, the port 4 will be adually closed off and the main yolume of t e fluid throttled by valve 14, while still for slight leakage through port 5, skirt 15 is seated. Further adjustment of stein 6 will tightly seat the main valve 11, While exerting additional spring pressure on the Seconda'r' valve 14. By this construction I am enabled to easily open and close a valve of very considerable size against heavy pressure, and to accurately control the flow or supply.

The device is very simple and cheap, composed of few parts, durable, and not liable to derangement, and ma be made in any desired size.

hat I claim is:

allowing after the 1. The combination with a valve chamber having a circulation opening therethrongh and a valve seat, of an adjusting stem having abutment-s and provided with a primary valve, and a relatively movable secondary valve mounted directly on said stem between said abutments, substantially as set forth.

2. The combination with a valve chamber havlng a circulation opening therethrough and a valve seat, of an adjusting stem having abutments and provided with a'primary valve, and a relatively movable spring-controlled valve mounted directly on said stem between said abutments, substantially as set forth.

3. The combination with a valve chamber having a circulation opening therethrough and a valve seat, of an adjusting stem having abutments and provided with aprimary valve, and a relatively movable secondary valve mounted directlyon said stem between said abutments, each of said valves being independently operative by said stem and adapted to engage said valve seat, substantially as set forth. 7

4. A valve casing having a cylindrical chamber, a supply port, a delivery port, a bushing encircling the delivery port, an ad justing stem having abutments and 'provided with a primary valve, and a longitudinally movable spring-pressed secondary valve mounted directly on said stem between said abutmeuts surrounding said primary valve and operable with said valve to engage the bushing, substantially as set forth.

5. The combination withthe valve seat bushing surrounding the outlet opening, of an adjusting stem having a terminal valve, collars secured to the stem above said valve, a secondary valve engaging the stem between said collars, and a spring between one Patented Sept. 9, 191a] of said collars and said secondary valve, substantially as set forth.

(3. 'lne combination with the valve seat bushing surrounding the outlet opening, of an adjusting stem having a terminal valve, collars secured to the stem above said valve, a. secondary valve engaging the stem between said collars, and packing means and a spring interposed between one-of said collars and said secondary valve, substantially 'as set forth.

7. The combination with a valve chamber having a circulation opening therethrough and a valve seat, of an adjusting stem providedvv'ith abutments and having secured to its terminal a positively-seating valve adapted to engage said valve seat, a secondary valve -mounted directly on the adjusting stein between said abutments and also adapted-to en age the valve seat, and cushioning devices tween said secondary valve and the stem adapting the stem to move after said secondary valve is seated, substantially as set forth.

8. The combination with a valve chamber having acirculation opening therethrough and a valve seat, of an adjusting stem having secured to its terminal a positively seating valve adapted to engage said valve seat, limiting abutments secured to the "valve stem beyond said positivel seating valve, a secondary valve mounted directly on the adjusting stem. between said abutments and also adapted to engage the valve seat, and cushioning devices between said secondary valve and one of said abutments adapting the stem to move after said secondary valve is seated, substantially as set forth.

In testimony "whereof I hereunto aifix my signature in the resence of two Witnesses.

SHARLES E. VANCE. Witnesses:

C. M. CLARKE, FRnnK. SIAUB. 

